JPH0881600A - Resin composition and use thereof - Google Patents

Abstract

PURPOSE: To obtain a resin compsn. excellent in oxygen barrier performance and impact resistance by blending an ethylene-vinyl alcohol copolymer with a specific polyolefin and an inorg. filler at a specific proportion. CONSTITUTION: A resin compsn. comprises (a) an ethylene-vinyl alcohol copolymer, (b) a polyolefin having at least one functional group selected from among boronic acid groups, borinic acid groups, boric acid-contg. groups each convertible into either a boronic acid group or a borinic acid group in the presence of water, and (d) an inorg. filler, provided that the (a) to (b) wt. ratio is 10/90 to 99/1 and the (d) to (a)+(b) wt. ratio is 0.1/99.9 to 50/50. A monolayer or multilayer structure made using a layer of this resin compsn. has an excellent impact resistance, good oxygen gas barrier properties even when subjected to sterilization under conditions simultaneously involving heat and water, such as boiling sterilization or retorting sterilization, and a good appearance after sterilization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin composition having excellent oxygen permeation preventive performance (barrier property) and impact resistance, a multi-layer structure and boiled sterilization, or storage stability and appearance when retort sterilized. It relates to an improved packaging material.

[0002]

2. Description of the Related Art Conventionally, in food packaging, metal cans, glass bottles, various plastic containers, etc. have been used as packaging containers, but in recent years, weight reduction, freedom of form,
From the viewpoint of impact resistance or cost, plastic containers are used as various food packaging containers.

However, while metal cans and glass bottles have zero oxygen permeation as a material, plastic containers are especially used in packaging forms such as pouches, lids and cups for boil sterilization and retort sterilization. ,
In particular, under the condition that heat and moisture simultaneously act as in hot water sterilization treatment or steam sterilization treatment that has been spotlighted as a food distribution form in recent years, its gas barrier property, particularly oxygen gas barrier property is insufficient. However, more than allowable oxygen invades the container, causing deterioration of the food contents due to oxygen, which becomes a problem in terms of storability such as flavor and freshness of food, and is currently used only for limited applications. is there. In addition, plastic containers have problems such as vibration during transportation and easy breakage due to impact due to dropping, so there are restrictions on the shape of the container,
There is also a big problem in terms of restrictions on increasing the size of the container.

That is, a polyvinylidene chloride polymer is a typical gas barrier resin used up to now, but it does not always have a sufficient oxygen barrier property, and the recent global environmental problems. From the viewpoint of (recycling is not possible, substances decomposed by incineration cause acid rain, etc.) are not preferable.

Ethylene-vinyl alcohol copolymer (EVOH), which is a representative of other gas barrier resins, also shows a good gas barrier property under low humidity, but it has a high gas barrier property such as boil sterilization or retort sterilization. When used under humidity and high temperature, there are major problems such as a sharp decrease in gas barrier property and a decrease in transparency. further,
EVOH has low impact resistance, and deterioration of the dust barrier property is caused by E.
There are problems such as easy bag breakage when the VOH layer is used thick and the container is upsized.

By the way, a multilayer laminate having a protective layer containing a desiccant is disclosed in JP-A-57-170748 and for the purpose of reducing the influence of water in boiling sterilization and retort sterilization and improving the gas barrier property. Japanese Examined Japanese Patent Sho 62-65
08, etc. However, since the moisture that has penetrated into the protective layer contacts the gas barrier layer, there is a concern that the moisture once absorbed will migrate to the gas barrier layer and the function of the gas barrier layer will deteriorate. In addition, the protective layer containing a desiccant tends to have extremely low impact resistance, which is problematic in terms of basic performance as a container.

A composition obtained by blending EVOH with an inorganic substance such as talc is disclosed in JP-B-51-21822 and JP-A-62-62822.
No. 143980, which is publicly known, does not disclose the technical idea of improving the gas barrier property by reducing the influence of water in the boil sterilization or retort sterilization. On the other hand, JP-A-3-281340 discloses that EVOH
It has been disclosed that a composition containing an inorganic substance such as talc having a specific property reduces the influence of water in boil sterilization or retort sterilization to improve the gas barrier property, but the basic performance as a container. There is a problem in terms of (impact resistance).

[0008]

Among the problems of the prior art, EVOH is a basic performance (impact resistance) as a container.
And the deterioration of the appearance of the package after boil sterilization or retort sterilization, and further to suppress the deterioration of the gas barrier property to a minimum.

[0009]

Means for Solving the Problems As a result of intensive studies by the present inventors, EVOH (a), a boronic acid group, a borinic acid group, and a boronic acid group or a borinic acid group in the presence of water can be added. A resin composition comprising a polyolefin (b) having at least one functional group selected from boric acid-containing groups and an inorganic filler (d), and other thermoplastic resins in the above (a), (b) and (d) The resin composition in which (c) is distributed has a significantly improved impact resistance, and the packaging material using the layer of the resin composition has no deterioration in appearance after boil sterilization or retort sterilization, and further has a gas barrier. I found that it is excellent in sex.

Hereinafter, the present invention will be described specifically. EVOH (a) used in the present invention is a saponified product of an ethylene-vinyl ester copolymer and has an ethylene content of 20 to
70 mol%, preferably 25 to 60 mol%, and a vinyl ester component having a saponification degree of 90% or more, preferably 95% or more can be used. When the ethylene content is less than 20 mol%, water resistance and wet heat resistance are deteriorated, gas barrier properties under high humidity are impaired, and it becomes difficult to maintain good melt processing characteristics. On the other hand, when it is more than 70 mol%, the water resistance and the moist heat resistance are improved, but the originally excellent gas barrier property is deteriorated. Also, the degree of saponification is 90%
If the amount is less than the above, the thermal stability is deteriorated, gels are likely to be generated during melt processing, and the gas barrier property and oil resistance are also deteriorated, which makes it difficult to enjoy the effects of the present invention.

As the vinyl ester, vinyl acetate can be mentioned as a typical example, but other vinyl esters such as lower or higher fatty acid vinyl ester (vinyl propionate, vinyl pipate, etc.) can be used. The vinyl ester may be used alone or in combination of two or more.

In the present invention, the EVOH (a) has an ethylene content of 20 to 70 mol%, a saponification degree of 95 mol% or more, and a vinylsilane content of 0.0001 to 0.5.
EVOH containing mol% silicon can be used more satisfactorily for the purposes of the present invention. As the olefinic unsaturated monomer containing silicon, conventionally known monomers such as those disclosed in JP-A-61-290046 can be used. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane,
Examples thereof include vinyltriacetoxysilane and vinyltripropionyloxysilane. The silicon content is selected according to each purpose, but a range of 0.0001 to 0.5 mol%, particularly 0.001 to 0.1 mol% is preferable.

Also, the EVOH melt index (A
According to STM D1238 65T, temperature 190 ° C,
Measured value measured under a load of 2160 g; hereinafter MI
Is not particularly limited, but 0.1 to 50 g / 10
Minutes. However, the melting point is around 190 ° C or 190
Those that exceed ℃ are measured at multiple temperatures above the melting point under a load of 2160 g, and the reciprocal of the absolute temperature is plotted on the abscissa in a semilog graph.
Plot the melt index (logarithm) as the vertical axis,
The value extrapolated to 190 ° C. is used. Furthermore, the EVOH referred to in the present invention may be modified with a small amount of a copolymerization monomer as long as the object of the present invention is not impaired, and as the modifying monomer, propylene, 1-butene, 1-hexene,
4-methyl-1-pentene, acrylic acid ester, methacrylic acid ester, maleic acid, phthalic acid, itaconic acid, higher fatty acid vinyl ester, alkyl vinyl ether, N-vinyl pyrrolidone, N-normal butoxymethyl acrylamide, N- (2- Dimethylaminoethyl)
Examples thereof include methacrylamides or quaternary products thereof, and N-vinylimidazole or quaternary products thereof.

Further, it is possible to use other additives (such as a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and other resins) in EVOH within a range not impairing the object of the present invention. Be free. In particular, as a gel prevention measure, hydrotalcite-based compounds, hindered phenol-based compounds,
It is preferable to add 0.01 to 1% by weight of one or more of hindered amine heat stabilizers and metal salts of higher fatty acid carboxylic acids (for example, calcium stearate, magnesium stearate, etc.).

In the present invention, a boronic acid group, a borinic acid group,
The polyolefin (b) having at least one functional group selected from a boron-containing group and a boron-containing group which can be converted into a boric acid group in the presence of water is specifically a boronic acid group, a boric acid group, or the presence of water. A polyolefin in which at least one functional group selected from the group consisting of a boronic acid group and a boron-containing group which can be converted into a borinic acid group below is bonded to the main chain, side chain or terminal by a boron-carbon bond. Of these, polyolefins having the functional group bonded to the side chain or the terminal are preferable, and polyolefins bonded to the terminal are most suitable. Here, the term "end" means one end or both ends. In addition, the carbon of the boron-carbon bond is derived from the base polymer of the polyolefin described later or from the boron compound reacted with the base polymer.
A preferable example of the boron-carbon bond is a bond between boron and a main chain or an alkylene group at a terminal or side chain. In the present invention, a polyolefin having a boronic acid group is suitable, and this point will be described below. In the present invention, the boronic acid group is represented by the following (I).

[0016]

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A boron-containing group (hereinafter simply referred to as a boron-containing group) which can be converted into a boronic acid group in the presence of water is hydrolyzed in the presence of water and is represented by the above formula (I). If it is a boron-containing group that can be converted to a boronic acid group,
As a typical example, a boronic acid ester group represented by the following general formula (II), a general formula (II
Examples thereof include a boronic acid anhydride group represented by I) and a boronic acid group represented by the following general formula (IV).

[0018]

Embedded image

[0019]

[Chemical 3]

[0020]

[Chemical 4]

[In the formula, X and Y are hydrogen atoms, aliphatic hydrocarbon groups (straight chain or branched alkyl groups having 1 to 20 carbon atoms, alkenyl groups, etc.), alicyclic hydrocarbon groups (cyclo Alkyl group, cycloalkenyl group, etc.), aromatic hydrocarbon group (phenyl group, biphenyl group, etc.),
X and Y may be the same group or different. Further, X and Y may be bonded. However, it is excluded when both X and Y are hydrogen atoms. R1, R2 and R3 represent the same hydrogen atom, aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group as those of X and Y, and R1, R2 and R2
, R3 may be the same or different. M represents an alkali metal or an alkaline earth metal.
Further, the above X, Y, R1, R2 and R3 may have other groups such as a carboxyl group and a halogen atom. }

Specific examples of the boronic acid ester group represented by the general formulas (II) to (IV) include a boronic acid dimethyl ester group, a boronic acid diethyl ester group, a boronic acid dipropyl ester group, a boronic acid diisopropyl ester group, and boron. Acid dibutyl ester group, boronic acid dihexyl ester group, boronic acid dicyclohexyl group, boronic acid ethylene glycol ester group, boronic acid propylene glycol ester group (boronic acid 1,2-propanediol ester group, boronic acid 1,3-propanediol ester Group),
Boronic acid ester groups such as trimethylene glycol ester boronic acid group, neopentyl glycol ester boronic acid group, catechol ester boronic acid group, glycerin ester boronic acid group, trimethylolethane ester boronic acid group; boronic acid anhydride group; boronic acid group And alkaline earth metal bases of boronic acid.

Among the above functional groups, a boronic acid ester group such as a boronic acid ethylene glycol ester group is particularly preferable from the viewpoint of compatibility with EVOH (d). The boron-containing group that can be converted to a boronic acid group in the presence of water is a polyolefin in water or a mixed liquid of water and an organic solvent (toluene, xylene, acetone, etc.) for a reaction time of 10 minutes to It means a group that can be converted into a boronic acid group or a borinic acid group when hydrolyzed for 2 hours at a reaction temperature of room temperature to 150 ° C.

The content of the functional group is not particularly limited,
0.0001 to 1 meq / g (milliequivalent / g) is preferable, and 0.001 to 0.1 meq / g is particularly preferable.
It is surprising that the compatibility, transparency, etc. of the resin composition are significantly improved by the presence of such a small amount of functional groups. Examples of the base polymer of the boronic acid-modified polyolefin (b) include olefin monomers represented by α-olefins such as ethylene, propylene, 1-butene, isobutene, 3-methylpentene, 1-hexene, 1-octene. Can be given.

The base polymer is used as a polymer composed of one, two or three or more of these monomers. Of these base polymers, especially ethylene-based polymers (ultra low density polyethylene, low density polyethylene,
Medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-acrylic acid copolymer metal salt (Na, K, Zn-based ionomer) ), Ethylene-propylene copolymers, etc.}, and propylene-based polymers are preferred.

The preferred melt index (MI) of the polyolefin (b) used in the present invention (210 ° C., 216
(Value measured under 0 g load) is 0.005 to 1000 g /
It is preferably 10 minutes, more preferably 0.1 to 100 g / minute.

Next, a typical method for producing a polyolefin polymer having a boronic acid group and a boron-containing group used in the present invention will be described. An olefin-based polymer having a boron-containing group that can be converted into a boronic acid group in the presence of a boronic acid group or water is a borane complex and a trialkyl borate which are added to an olefin-based polymer having a carbon-carbon double bond under a nitrogen atmosphere. It is obtained by reacting an ester to obtain an olefin polymer having a boronic acid dialkyl ester group, and then reacting it with water or alcohols. When an olefin polymer having a double bond at the terminal is used as a raw material in this production method, an olefin polymer having a boronic acid group at the terminal or a boron-containing group which can be converted into a boronic acid group by the presence of water is obtained. If a olefin polymer having a double bond in the side chain or main chain is used as a raw material, a polyolefin polymer having a boronic acid group in the side chain or a boron-containing group which can be converted into a boronic acid group in the presence of water. Can be obtained.

As a typical method for producing an olefin polymer having a double bond as a raw material, 1) a method utilizing a small amount of double bond present at the terminal of an ordinary olefin polymer;
2) A process for thermally decomposing an ordinary olefin-based polymer under anoxic conditions to obtain an olefin-based polymer having a double bond at a terminal; 3) Olefin by copolymerization of an olefin-based monomer and a diene-based polymer A method for obtaining a copolymer of a base monomer and a diene monomer. Regarding 1), a known olefin polymer production method can be used,
In particular, a production method using a metallocene-based polymerization catalyst as a polymerization catalyst without using hydrogen as a chain transfer agent (for example, DE40
30399) is preferred. Regarding 2), it can be obtained by a known method (for example, US2835659, 3087922) by thermally decomposing an olefin-based polymer at a temperature of 300 ° C to 500 ° C under oxygen-free conditions such as a nitrogen atmosphere and a vacuum condition. Regarding 3), a method for producing an olefin-diene copolymer using a known Ziegler catalyst (for example, JP-A-50-44281, DE302127).
3) can be used.

As the borane complex, borane-tetrahydrofuran complex, borane-dimethylsulfide complex, borane-pyridine complex, borane-trimethylamine complex, borane-triethylamine and the like are preferable. Among these, borane-triethylamine complex and borane-trimethylamine complex are more preferable. The amount of the borane complex charged is preferably in the range of 1/3 equivalent to 10 equivalents with respect to the double bond of the olefin polymer. As the boric acid trialkyl ester, boric acid lower alkyl ester such as trimethyl borate, triethyl borate, tripropyl borate, and tributyl borate is preferable. The amount of the trialkyl borate ester charged is preferably in the range of 1 to 100 equivalents with respect to the double bond of the olefin polymer. The solvent is not particularly required to be used, but when it is used, a saturated hydrocarbon solvent such as hexane, heptane, octane, decane, dodecane, cyclohexane, ethylcyclohexane, decalin is preferable. The reaction for introducing the boronic acid dialkyl ester group into the olefin polymer having a double bond has a reaction temperature of room temperature to 300 ° C., preferably 100 to 25.
The reaction is carried out at 0 ° C. for a reaction time of 1 to 10 hours, preferably 5 to 5 hours.

The conditions for reacting water or alcohols are usually organic solvents such as toluene, xylene, acetone and ethyl acetate as reaction solvents, and water or alcohols such as methanol, ethanol and butanol; ethylene glycol, 1, 2-propanediol, 1,3
-Propanediol, neopentyl glycol, glycerin, trimethylolethane, pentanithritol,
Using polyhydric alcohols such as dipentanyllithitol in an excess of 1 to 100 equivalents or more with respect to the boronic acid group,
It can be obtained by carrying out the reaction at a temperature of room temperature to 150 ° C. for about 1 minute to 1 day. The boron-containing group that can be converted to a boronic acid group among the functional groups is a reaction time of 10 minutes to 2 hours in water or a mixed solvent of water and an organic solvent (toluene, xylene, acetone, etc.). , Reaction temperature room temperature to 150
It means a group which can be converted into a boronic acid group when hydrolyzed under conditions of ° C.

Examples of the thermoplastic resin (c) used in the present invention include a polyolefin resin, a polyamide resin, a polyester resin, a polycarbonate resin, a polyvinyl chloride resin, and the like. Is preferably used.

It is usually difficult to uniformly mix these components (c) with EVOH (a), and it is difficult to obtain a molded article having excellent impact resistance. Even when the component (c), especially the component having poor compatibility with the EVOH (a), is blended with the EVOH (a), it is possible to obtain a molded article having excellent impact resistance and excellent barrier properties. Further, the characteristics possessed by the component (c) can be added. As the polyolefin resin of the thermoplastic resin (c) used in the present invention, mainly high-density or low-density polyethylene, polypropylene, polybutene-1, etc. and ethylene, propylene,
Although it is a copolymer of α-olefins selected from butene-1, hexene-1, etc., as a copolymerization component with these α-olefins, diolefin, N-vinylcarbazole, vinyl chloride, vinylidene chloride, Vinyl acetate,
Vinyl compounds such as styrene, acrylonitrile and vinyl ether, unsaturated carboxylic acids such as maleic acid, acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid and itaconic acid, their esters or their anhydrides, or their hydroxyl groups or epoxy groups. It is possible to add those that have been added. Specifically, a copolymer of a graftable monomer and a polyolefin or α-olefin /
Examples thereof include copolymers containing 50% by weight or more of α-olefin such as an ionomer resin which is a reaction product of an α, β-unsaturated carboxylic acid copolymer and an ionic metal compound.

The polyamide resin of the thermoplastic resin (c) used in the present invention is a polymer having an amide bond, for example, polycaproamide (nylon-
6), polyundecane amide (nylon-11), polylauryl lactam (nylon-12), polyhexamethylene adipamide (nylon-6,6), polyhexamethylene sebacamide (nylon-6,12). Homopolymer, caprolactam / lauryllactam copolymer (nylon-6 / 12), caprolactam / aminoundecanoic acid copolymer (nylon-6 / 11), caprolactam /
ω-aminononanoic acid copolymer (nylon-6,9), caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 6,6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer Polymer (nylon-
6/6, 6/6, 12) and the like. These polyamide resins can be used alone or in combination of two or more. The thermoplastic resin (c) is a mixture of two or more different types of resins, for example, polyolefin resin and polyamide resin, specifically nylon-6 and low density polyethylene, depending on the purpose. You can also

If desired, additives may be added to the resin composition. Examples of such additives may include antioxidants, plasticizers, heat stabilizers, UV absorbers, antistatic agents, lubricants, colorants, or other polymeric compounds, which may be used in the invention. It can be blended within a range that does not impair the action and effect. The following are specific examples of the additive.

Antioxidants: 2,5-di-t-butylhydroxine, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis- (6-t-butylphenol), 2, 2'-methylene-bis- (4-methyl-6-
t-butylphenol), octadecyl-3- (3 ′,
5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-butylphenol) and the like. UV absorber: ethylene-2-cyano-3,3'-diphenyl acrylate, 2- (2'-hydroxy-5'-
Methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl)
Benzotriazole, 2- (2'-hydroxy-3'-
t-butyl-5'-methylphenyl) 5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone and the like. Plasticizer: dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester, etc. Antistatic agent: pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins,
Polyethylene oxide, carbowax, etc. Lubricants: ethylene bis stearamide, butyl stearate, etc. Coloring agent: carbon black, phthalocyanine, quinacridone, indoline, azo pigment, red iron oxide, etc. Many other high molecular compounds can also be blended to such an extent that the effects of the present invention are not impaired.

Next, the inorganic filler (d) used in the present invention
Will be described. As the inorganic filler, it is important that the weight average flake diameter is 30 μm or less and the weight average aspect ratio is 3 or more. When the weight average flake diameter is larger than 30 μ, the blending property with EVOH and the film forming property after blending are deteriorated, and when the aspect ratio is smaller than 3, the modifying effect becomes insufficient. In addition,
According to the scanning electron microscope, the weight average flake diameter and aspect ratio of the above-mentioned inorganic filler have almost no difference between the value of the raw inorganic filler before mixing with EVOH and the value of the inorganic filler present in the multilayer package. It has been confirmed.

Therefore, in the present invention, the weight average flake diameter and the weight average aspect ratio of the inorganic filler are
It means the value of the inorganic filler before kneading with EVOH or the value of the inorganic filler present in the multilayer package. The weight average flake diameter of the inorganic filler is preferably 15
It is μ or less, and more preferably 5 μ or less. The lower limit value is not particularly limited, but is preferably 0.5 μ, more preferably 1 μ. The weight average aspect ratio is preferably 5 or more, more preferably 10 or more. The upper limit is not particularly limited.

The weight-average flake diameter in the present invention is a powder (in this case, an inorganic filler) is classified by a micro sieve or sieve having various openings, and the result is Ro.
It is the value corresponding to the mesh opening L50 of the microsieve or the sieve through which 50% by weight of the total weight of the powder used for the measurement is plotted in the sin-Rammlar diagram. That is, the weight average flake diameter L of the powder is (II) or (III
) Is defined by the formula. L = L50 (in case of micro-sieve) (II) L = 21/2 · L50 (in case of sieve) (III) Here, the part of the powder with a large particle size is classified by the sieve, and the particle size is The fine part of is classified by microsieve.

On the other hand, the weight average aspect ratio α of the powder in the present invention is expressed by the formula (IV) from the weight average flake diameter L and the weight average flake thickness d of the powder measured by the following method. It is a calculated value. α = L / d (IV)

The weight average flake thickness d of the powder in the formula (IV) is C.I. E. Capes et al. Reported a single-particle water surface membrane method {C. E. Capes and R.A. C. Col
eman. Ind. Eng. Chem. Funda
m. , Vol. 12, No. 1, p. 124-126
It is a value calculated from the equation (V) using the area S of the flakes occupied on the water surface measured by (1973)}. d = W / (ρ (1-ε) · S) (V)

Here, W is the weight of the powder used for measurement, ρ is the specific gravity of the powder, and (1-ε) is the occupancy when the powder is in the closest packed state on the water surface. For the body, 0.9 was generally used in the calculation.

In the present invention, examples of the inorganic filler include talc, clay, sericite, glass flake, mica and the like. Among them, talc and clay are preferable because they impart more excellent impact resistance and thermoformability. is there.

In the present invention, the weight ratio of the components (a), (b), (c) and (d) {including the case where the component (C) is 0%} is (a) / {(b ) + (C)} = 10
/ 90 to 99/1, preferably 30/70 to 95/5. When the EVOH (a) content is 10% by weight or less, the gas barrier property is not sufficient, and when it is 99% or more, the effect of improving water resistance, hot water resistance and impact resistance becomes insufficient.
Furthermore, the weight ratio of (d) is (d) / {(a) + (b) +
(C)} = 0.1 / 99.9 to 50/50, preferably 0.5 / 99.5 to 40/60. When the content of the inorganic filler (d) is 0.1% by weight or less, the effect of improving water resistance, hot water resistance, impact resistance and gas barrier property is insufficient, and when it is 50% by weight or more, on the contrary, impact resistance and gas barrier property are improved. -The sex decreases. Also, (b) / (c) is 1/9
It is selected from the range of 9 or more, preferably 10/90 or more.
When the content of the boron group-containing polyolefin (b) is 1% by weight or less, the effect of improving water resistance, hot water resistance and impact resistance becomes insufficient.

Next, a method for obtaining the resin composition will be described. In order to disperse the inorganic filler in EVOH uniformly without agglomerating, and to form a substantially two-dimensional thin layer so that the inorganic filler is laminated in parallel to the layer surface direction of the intermediate layer, the resin composition is prepared. The kneading operation of is extremely important.
First, there is a method of melt-kneading EVOH and an inorganic filler (particularly talc) at a melting point of EVOH or higher (melt-kneading method). As this method, an EVOH powder, a pellet and an inorganic filler are mixed with an ordinary mixer, For example, in a Henschel mixer, a super mixer, or by mixing an EVOH melt with an inorganic filler to form a master, which is mixed with a powder, pellets, or melt of EVOH, and then the mixture. , And a method of kneading at a temperature equal to or higher than the melting point of EVOH. It is also possible to directly introduce the EVOH and the inorganic filler into the kneader and knead them without previously mixing the EVOH and the inorganic filler as described above.
As a kneading machine for obtaining a composition having a high degree of dispersion without agglomerates of inorganic filler, a continuous kneading machine such as a continuous intensive mixer or a kneading type twin-screw extruder (in the same direction or in different directions) is used. Is most suitable, but a batch type kneader such as a Banbury mixer, an intensive mixer, a pressure kneader or the like can be used.

The multilayer structure of the present invention means (a),
At least one resin composition layer comprising (b), (d) or (a), (b), (c) and (d) is included, and a thermoplastic resin layer, particularly a heat resistant thermoplastic resin layer is added to the resin composition layer. It is a laminate. In this case, a scrap recovery layer and an adhesive resin layer can be provided as needed. When the resin composition layer is (B), the thermoplastic resin layer is (H), the scrap recovery layer (R) and the adhesive resin layer (A), a multilayer structure having the following layer structure is a typical example. Can be given as.

2 layers H / B 3 layers H / A / B, R / A / B, H / B / R, H / B /
H 4 layer H / R / A / B, H / R / B / H, H / R / B /
R 5 layer H / R / A / B / H, H / R / A / B / R, H /
R / B / A / H, H / A / B / A / H, H / R / B / R
/ H 6 layers H / R / A / B / A / H, H / R / A / B / A /
R 7 layer H / R / A / B / A / R / H However, the layer structure is not limited to the above.

Examples of the thermoplastic resin used in the thermoplastic resin layer (H) include the above-mentioned thermoplastic resin (c), and also EVOH (a). The adhesive resin used in the adhesive resin layer (A) is not particularly limited, but may be a polyurethane-based or polyester-based one-component or two-component curable adhesive, unsaturated carboxylic acid or The anhydride (maleic anhydride, etc.) is converted into an olefin polymer or copolymer [polyethylene {low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ultra low density polyethylene (SLDP)
E)}, ethylene-vinyl acetate copolymer, ethylene-
What was grafted to the (meth) acrylic acid ester (methyl ester or ethyl ester) copolymer] is preferably used.

As the recovered material of the scrap recovery layer (R), a multilayer container of the present invention, for example, a hollow container, a tubular container, and a packaging container obtained by further processing the tubular product are formed. There are molding loss parts when making products, and crushed products of scrap recovered products after being used by general consumers. Further, when the composition (B) is contained in the recovery layer, excellent recoverability is obtained.

The method for obtaining a single-layer or multi-layer structure using the resin composition of the present invention is not particularly limited. For example, a molding method practiced in the field of general polyolefins, for example, , T-die molding, inflation molding, blow molding, stamping molding,
Blow molding, stretch blow molding, axial expansion blow molding, injection molding and the like can be mentioned. Particularly when a multilayer container is obtained, a coextrusion sheet molding method, a coextrusion pipe molding method, a coextrusion molding method, a coextrusion blow molding method, Co-injection molding, extrusion coating molding, dry laminate molding can also be adopted. Etc. Further, the thickness configuration of the multilayer structure is not particularly limited, but in consideration of moldability and cost, the thickness ratio of the layer made of the resin composition to the entire thickness is about 1 to 30%. It is suitable.

The multi-layer structure of the present invention is suitable for use as a packaging material for boil sterilization or retort sterilization, since no abnormal appearance occurs. After filling the packaging material with contents, especially food, degas the inside with known means as necessary, or after replacing the inside with an inert gas such as nitrogen gas or carbon dioxide, by means such as heat sealing. It is sealed and subsequently boiled, for example below 100 ° C. or under temperature conditions above 100 ° C., in particular 10
Sterilized with hot water or steam (especially high temperature, high pressure steam sterilization) such as retort treatment performed at 5 to 135 ° C,
A package can be obtained. Further, it can be used for other various food, cosmetics, pharmaceuticals, packaging containers for medical devices, medicines, gasoline containers, pipes and the like.

[0051]

EXAMPLES Next, the present invention will be described in more detail with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to these examples.

Synthesis Example 1 Synthesis of Ultra Low Density Polyethylene Having Boronic Acid Ethylene Glycol Ester Group at Terminal: Ultra low density polyethylene {MI 7 g / 10 min (210 ° C., load at 210 ° C., load in a separable flask equipped with a condenser, stirrer and dropping funnel. 2160 g) density 0.89, amount of terminal double bonds 0.048 meq / g} 1
After degassing by charging 000 g and decalin 2500 g and reducing the pressure at room temperature, nitrogen substitution was performed. To this, 78 g of trimethyl borate and 5.8 g of borane-triethylamine complex were added, and after reacting at 200 ° C. for 4 hours, a distillation tool was attached and 100 ml of methanol was slowly added dropwise. After completion of methanol dropping, by vacuum distillation,
Low boiling point impurities such as methanol, trimethyl borate, and triethylamine were distilled off. Further, 31 g of ethylene glycol was added, the mixture was stirred for 10 minutes, and then reprecipitated in acetone,
By drying, ultra low density polyethylene (boronic acid-modified polyethylene) (B-acid polyethylene glycol ester amount 0.027 meq / g, MI 5 g / 10 min) (B
-PE) was obtained.

Synthesis Example 2 Synthesis of polypropylene having a double bond at its end: Polypropylene (MI 0.5 g was added to a twin-screw type extruder having a screw diameter of 25 mm and a feeder equipped with a nitrogen inlet tube.
/ 10 minutes, density 0.90) was supplied, and extrusion pelletization was performed under the following conditions. Temperature condition (° C.): C1 / C2 / C3 / C4 / C5 / die = 250/370/370/350/270/210 Discharge rate: 1.45 kg / h Screw rotation speed: 235 rpm Nitrogen flow rate: 5 L / min Obtained The pellets were immersed in hexane for 1 day and then dried to give a double bond amount of 0.012 meq / g, MI20.
Polypropylene (B-PP) of g / 10 minutes was obtained.

Synthesis of polypropylene having a boronic acid ethylene glycol ester group at the end A separable flask equipped with a condenser, stirrer and dropping funnel was charged with 1000 g of polypropylene having a double bond at the end of the synthesis example and 2000 g of decalin, and decompressed at room temperature. After degassing by performing the above, nitrogen substitution was performed. To this, 40 g of trimethyl borate and 2.9 g of borane-triethylamine complex were added, and after reacting at 200 ° C. for 4 hours, a distillation tool was attached and 100 ml of methanol was slowly added dropwise. After the addition of methanol was completed, low-boiling-point impurities such as methanol, trimethyl borate, and triethylamine were distilled off by vacuum distillation. Add 31 g of ethylene glycol and add 1
After stirring for 0 minutes, re-precipitation in acetone and drying were performed to obtain a boronic acid ethylene glycol ester group content of 0.01
Polypropylene (boronic acid-modified polypropylene) (B-PP) of 2 meq / g and MI 21 g / 10 min was obtained.

Example 1 EVOH having an ethylene content of 31 mol%, a saponification degree of a vinyl acetate component of 99.5 mol%, and an MI of 1.6 g / 10 min.
60 parts of the powder of (a), 20 parts by weight of the B-PP powder (b) obtained in Synthesis Example 2, and 20 parts of a talc powder (d) having a weight average flake diameter of 3 μ and a weight average aspect ratio of 15 were obtained. After premixing in a Hensiel mixer, high speed mixing was performed to obtain a mixture. In a mixing chamber with an inner diameter of 30 mm,
Mixing extrusion pelletization is performed by using a two-stage twin-screw different-direction continuous extruder having two mixing rotors and a degassing mechanism between the two rotors, and a single-screw extruder connected to this. The product pellet was obtained. The mixing rotor adopted at this time has a tip clearance of 3 with the mixing chamber.
mm, the kneading temperature (outlet temperature) is 205 to 23
The measurement was carried out at 0 ° C., the rotor rotation speed was 300 to 450 rpm, and the specific energy was 0.1 to 0.3 KWh / Kg. Then, after the blended pellets were dried at 105 ° C. (water content was 0.2%), the mixture was put into a three-kind five-layer coextrusion sheet film-forming machine to prepare a five-layer original sheet. did. The thickness of the original sheet is a polypropylene (PP) layer having a thickness of 300 μ (Mitsubishi Noblen YP220), an adhesive resin layer having a thickness of 50 μ (Adma-QF500), an EVOH composition layer having a thickness of 50 μ, and a thickness of 50 μ. Of the adhesive resin layer and a PP resin layer having a thickness of 300 μ are sequentially laminated. The obtained sheet was thermoformed (175 ° C-drawing ratio = 1/1) to obtain a cup having a good appearance. Add water from the above cup, 20 ℃
As a result of measuring the gas barrier property of the EVOH composition layer with a 10/50 type manufactured by Mocon Co., Ltd., the humidity was controlled for 1 month in a −65% RH atmosphere, and 0.8 cc. 20 μ / m2. day. Atm was good. Next, 1 in the cup as contents
0% ethylene glycol water was added, the top was covered, and the periphery was sealed. This is a retort device (manufactured by HISAKA CORPORATION,
Using a high temperature and high pressure cooking sterilization tester RCS-40RTGN), sterilization treatment was carried out at 95 ° C. for 30 minutes. The pouch after the sterilization treatment had no particular defects in appearance and morphology.
As a result of measuring the oxygen permeability of the EVOH composition layer by controlling the humidity of the cup in a 20 ° C.-65% RH atmosphere for 1 month,
1.0 cc. 20 μ / m2. day. Atm, indicating good gas barrier properties. Also, the cup above -2
After cooling to 0 ° C and dropping it onto the concrete floor, 2m
The above drop bag breaking resistance was recognized. Furthermore, the morphology (weight average flake diameter, weight average aspect ratio) of talc obtained by firing the intermediate layer of the cup in an electric furnace was observed with a scanning electron microscope, and almost no difference was observed from that before mixing. It was In addition, cutting several arbitrary parts of the cup and observing the intermediate layer of the cross section with a scanning electron microscope, talc did not aggregate, and a thin layer of talc was laminated almost parallel to the intermediate layer film surface. In addition, a large number of laminated regions were also seen, and the dispersibility of talc (estimated to have an effect on the reduction of oxygen gas permeability) was good. The above results are shown in Tables 1-3.

Example 2 The powder (b) of B-PP used in Example 1 was changed to the powder (b) of B-PE obtained in Synthesis Example 1, and 3 types 5 were used.
3 layer, 5 layer multi-layer direct blow molding was used instead of 3-layer multi-layer sheet molding.
PE layer (Hi-Zex 5000), recovery layer having a thickness of 200 μ, (Reg.) Adhesive resin layer having a thickness of 50 μ (Adma-NF450), EVOH composition layer having a thickness of 50 μ, adhesive resin having a thickness of 50 μ A bottle having a layer structure in which HDPE resin layers each having a layer and a thickness of 300 μ were sequentially laminated was obtained. The bottle was conditioned at 20 ° C. and 65% RH, and the oxygen permeability of the EVOH composition layer was measured. As a result, 0.8 cc. 20μ
/ M2. day. Atm, indicating good gas barrier properties. Further, when the cup was cooled to -40 ° C and dropped on the concrete floor, drop puncture resistance of 6 m or more was recognized.

Examples 3 to 4 Bottles were obtained under the same conditions as in Example 2 except that shown in Tables 1 and 2. Table 3 shows the results.

Comparative Examples 1 to 3 Cups were obtained under the same conditions as in Example 1 except that shown in Tables 1 and 2. Table 3 shows the results.

Comparative Example 4 A bottle was obtained under the same conditions as in Example 2 except that shown in Tables 1 and 2. Table 3 shows the results.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

[Table 3]

[0063]

The single-layer or multi-layer structure using the resin composition layer of the present invention is excellent in impact resistance and is sterilized under conditions such that heat and water simultaneously act such as boil sterilization and retort sterilization. Also has a good oxygen gas barrier property and has an excellent appearance after sterilization treatment.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 3/00 C08L 29/04 101/00 LSZ

Claims (4)

[Claims] 1. At least one selected from an ethylene-vinyl alcohol copolymer (a), a boronic acid group, a boric acid group, a boric acid group in the presence of water, and a boric acid-containing group that can be added to the boric acid group. A polyolefin (b) having one functional group and an inorganic filler (d), and (a)
Weight / (b) weight is 10/90 to 99/1,
Weight of (d) / total weight of (a) and (b) is 0.1 / 9
The resin composition which is 9.9-50 / 50. 2. At least one selected from an ethylene-vinyl alcohol copolymer (a), a boronic acid group, a boric acid group, a boric acid group in the presence of water, and a boric acid-containing group that can be added to the boric acid group. -Functionalized polyolefin (b), thermoplastic resin (c) and inorganic filler (d)
And the total weight of (a) / (b) and (c) is 10/90 to 99/1, (d) weight / (a),
The total weight of (b) and (c) is 0.1 / 99.9-5.
A resin composition having a weight ratio of 0/50, (b) / (c) of 1/99 or more. 3. A multilayer structure having at least one layer of the resin composition according to claim 1 and a layer of a heat resistant thermoplastic resin. 4. A packaging material for boil sterilization or retort sterilization, which comprises the multilayer structure according to claim 3.